1. Field of the Invention
The present invention relates generally to environmental protection apparatus, and, more particularly, to a separator unit for separating and containing the liquid portions of a gas/liquid mixture expelled from a gas well during blow-off procedures which expel from the well head excessive fluid blockage in the form of oil and/or salt water, such blockage reducing gas pressure at the well head and thus reducing production of the gas well.
2. Description of the Prior Art
In the normal operation of a natural gas well, once the gas is pumped out of the well, the gas is piped to a production line whereat processing of the gas commences. As a normal consequence of the pumping operations, varying amounts of oil and water occurring in the well are also pumped out of the well. In most instances, the amount of liquid pumped out of the well is not excessive and may be separated from the gas at the well head by using a relatively small volume separator tank without interrupting normal pumping operations. At certain times, however, an excessive amount of liquid is pumped out of the well. During such times, the gas pressure of the natural gas at the well head drops due to the lessened proportion of gas pumped out of the well. When this situation arises, a special procedure is required to remove the liquid from the well head. A dedicated piping apparatus, commonly referred to as a blow-off line, connects the well head to an oil storage tank. During those times in which the gas pressure at the well head is lessened, indicative of a high volume of liquid at the well head, a valve is opened to allow the liquid to flow through the blow-off line into the oil storage tank. The oil storage tank is vented so that the interior thereof is normally at atmospheric pressure while at the same time, the pressure at the well head, even at a reduced pressure, is well above atmospheric pressure. Such a pressure differential causes the gas/liquid mixture to flow through the blow-off line and into the oil storage tank at a high velocity. The volume of the oil storage tank generally can contain the volume of the liquid portion of the gas/liquid mixture expelled during blow-off if the pressure of the gas/liquid mixture is not too great. However, if the pressure becomes too excessive, a certain amount of this gas/liquid mixture will be expelled through the vents of the oil storage tank which vent the interior of the storage tank to the atmosphere. Such a discharge causes environmental contamination as well as a high level of noise.
A means for preventing this discharge into the environment would eliminate the environmental contamination caused by such discharges.
There is also a need for providing a containment vessel for holding scale, liquid and other contaminants which are removed from the insides of gas production pipelines during normal maintenance operations. As is known, in the normal maintenance of a gas production pipeline, it is common to drive a pig under pressure through the section of the pipeline to be cleaned or maintained. As it travels through the pipeline, the pig removes scale and other deposits from the interior wall of the pipeline. Also, any liquid which has collected in the pipeline is forced through the pipeline ahead of the pig as the pig travels therethrough. Over long stretches of pipeline, the volume of the collected fluid and/or scale which is forced through the pipeline may become quite significant. Thus, a need exists for providing a large volume containment vessel which may receive liquid, scale and other contaminants from a gas production pipeline during maintenance thereof.
It is therefore the object of the present invention to provide a means by which the exit of environmentally damaging discharge from an oil storage tank may be prevented during gas well blow-off operations.
It is a further object of the invention to provide a means for preventing high levels of noise from being produced during gas well head blow-off operations.
It is a further object of the invention to provide a large volume vessel which communicates with a gas pipeline for receiving liquid, scale and other contaminants removed from the pipeline during maintenance thereof.
Still other objects and advantages will become apparent when one considers the attached drawings and description of the invention presented hereinbelow.